Pneumatic propulsion means.



No. 630,821. Patented Aug. 8, |899.

J. C. WALKER.

PNEUMATIC PROPULSION MEANS.

(Application med Jan. 1o, w99.) (N0 Model.)

mz Nunms PETERS w. PHofuLTNn.. WASHINGTON, n. c.

Nrrnn STATES JAMES C. XVALKER, OF VACO, TEXAS.

PN EUNlATlC PROPU LSION lVl EANS.

SPECIFICATION forming part of Letters Patent No. 630,821, dated August 8, 1899. Application led January l0, 1899. Serial No. 701,772. (No model.)

To all whom, t may concern:

Be it known that l, JAMES C. WTALKER, residing at Vaco, in the county of McLennan and State of Texas, have invented a new and Improved Pneumatic Propulsion Means, of which the following is a specification.

This invention relates to improvements in that class of propeller means including shiphulls having external air pockets or channels adapted to direct currents of air to aid in the propulsion of the ship, and particularly to that kind as described in my copending application, Serial No. 680,306, filed MaylO, 1898.

This invention seeks to provide a novel arrangement and construction of combined propeller and air-discharging means whereby the propeller while performing all of the necessary functions as a propeller also serves to act as a lead for conveying air-current to the rear of the blade, so as practically to avoid all possibility of the creation of vacuum or cavities at the rear of the said propeller, and in consequence increases its propulsive action.

The invention consists in the peculiar construction and novel arrangement of propulsion mechanism, as will be first described, and then pointed out in the appended claims, reference being had to the accompanyingdrawings, in which- Figure-1 is a section of the ships hull with my improved propeller in position. Fig. 2 is a vertical longitudinal section of the propeller-shaft and its blades. Fig. 3 is a front end View of the propeller-shaft. Fig. et is a rear face view of the propeller, and Fig. 5 is a detail section taken on the line 5 5 of Fig. 4.

Referring to the accompanying drawings, Aindicates the boat body or hull, which may be of any well-known form, but preferably of that kind havinglateral air-ducts for leading a current of air to discharge at the rear of the stern to aid the propulsion of the ship-such, for example, as described in my other application referred to.

The propeller proper comprises a shaft formed of a steel tube H, which is held to turn within the casing, and the said propeller is driven by a gear h', Xedly connected to the inner end of the tube H by a key h2, (see Fig. 2,) which gear 7i' is driven by any suitable power. The casing in which the steel tube Il is held to turn consists of a series of wedge-sections h, closely iitting against each other and held on the tube H by the bands e2, which engage the sections h near the forward end, the rear part of the sections hbeing free of such fastening-bands c2, whereby to allow the rear part of the shaft to have a limited springy action, and the complete tubular casing may be held the more stable by wire wrappings wound about the sections 7L,which serve to strengthen the sections, as indicated in dotted lines in Figs. 2 and 5. The shaft is made tapering from its inner to the outer end, and the said outer end terminates in a contracted nozzle H', formed of a series of radially-extending discharge-openings e, the purpose of which will presently appear. The sections h in practice are mounted in suitable bearings. (Not shown.)

The purpose of making the shaft tubular is to make it serve as a continuation of the air-supply pipe B, which connects with the blower B' or other similar device, which blower, when the shi ps hull has external airchannels, is also connected with the said propeller-shaft.

By providing means for discharging air directly through the stern of the boat (as through the tubular propeller) it is obvious that the air thus discharged will fill any cavities or vacuum which may be created directly at the rear of the propeller-blade, such action of the air serving to positively reduce the danger of the creation of a vacuum at the stern or directly in the rear of the blade to a minimum and by reason thereof thereby overcoming the retarding action of the vessel which is incident in the usual construction of vessels, especially those driven by screw propulsion. The propeller-shaft is mounted within the hull and may be driven in any approved manner.

On the outer end of the shaft is fitted a boss e3, having apertures 610, alining the orifices e in the propeller-shaft hub Z, the orilices e opening into the radial arms e5 of the propeller-blades, the construction of which, in connection with the hollow shaft, forms the essential feature of this invention. The arms e5 are tubular and at their ends carry hollow blades el?, the impact-faces of which are disposed at a proper angle transversely to the radial axis, their rear faces having air-escape IOO orices es, whereby to permit the air to discharge in such manner as to constantly iill whatever vacuum or cavities might be created around the blade by reason of the displacement of the water. Said radial arms'e5 are made diamond or angle shape in cross-section, as indicated in dotted lines in Fig. 2, with their sharp edges set in the same pitch as the blades, whereby to split the water in the same plane with the blades.

The front end of the tubular shaft H has a back or check valve f to close the bore of the shaft and prevent water coming up therein in case of back movement.

lVhile a powerfulair-blast is obtainable by connecting the hollon7 shaft with the blower or other air-compressor, yet it is manifest that a strong induced blast can be obtained without connecting the blower to the shaft by reason of the revolution of the propeller-blades, which serves to create an induction at the front end of the shaft H and thereby draw in air, which as it is disseminated through the hollow radial arms and the blades of the propeller discharges into any space which might form in the water as the blades rotate therein to iill the vacuum created,as heretofore stated, it being obvious that by drawing in the air from the ships hold such hold will be constantly ventilated as the foul airis drawn off through the shaft.

By constructing the ships hull and the propulsion means asdescribed the resistance of the water on the vessel is reduced to a minimum and the back or suction action incident to the ordinary form of vessels and propellers is so materially overcome as to provide for a more uniform and rapid speed with a greatlydecreased driving energy.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

l. As an improvement in ship propulsion; in combination with the ships hull; the hollow propeller-shaft having hollowr propellerblades and hollow arms, held in communical tion with the shaft, said blades having discharge-openings'in their rear faces, and the shaft having a directly-rearward air-dischargi ing nozzle, as specified.

2. In aship-propulsion means of the character stated; a propeller-shaft comprising an outwardly-tapering hollow shaft, the outer end of which terminates in zle, the inner end having a back-pressure valve; radial outlets on the rear end; hollow raidial arms communicating with such outlets, said arms carrying hollow blades having discharge-orifices, substantially as shown and for the purposes described.

3. In a ship-propulsion means of the charaeter stated; a propeller comprising a hollow outwardly-tapering shaft, its outer end terminating in a discharge-nozzle, said outer end having radial air-discharges; a boss secured on such end having air-orices communicating with the radial propeller-shaft outlets; a series of longitudinal wedge-sections h, closely against each other and held tightly on the hollow shaft; and a wire wrapping extending around said sections, substantially as shown and for the purposes described.

4. An improved propeller-shaft in ship-propulsion means of the character described,

comprising a hollow shaft tapering toward its outer end, said end terminating in a discharge-nozzle blowing directly rearward and having at said end radial air-outlets, its inner or feed end having a back-pressure valve; l a boss mounted on its outer end having radial l discharges am; radial hollow arms communieating with the discharges el, and hollow blades secured to said arms, having discharge-orifices; said blades and arms being l -made of diamond shape in cross-section, all being arranged substantially as shown and for the purposes described.

JAMES C. lVALKER. XVitnesses:

RICHD. I. MUNRon, i R. P. DUNCAN.

a discharge-noz- 

